scholarly journals Analytical Investigation of a Novel System for Combined Dew Point Cooling and Water Recovery

2021 ◽  
Vol 11 (4) ◽  
pp. 1481
Author(s):  
Aleksandra Cichoń ◽  
William Worek
Keyword(s):  
Energy Consumption ◽  
Convective Heat Transfer Coefficient ◽  
Specific Energy Consumption ◽  
Analytical Investigation ◽  
Dew Point ◽  
Energy Utilization ◽  
Coefficient Of Performance ◽  
Air Cooling ◽  
Water Recovery ◽  
Utilization Factor

This paper presents the analytical investigation of a novel system for combined Dew Point Cooling and Water Recovery (DPC-WR system). The operating principle of the presented system is to utilize the dew point cooling phenomenon implemented in two stages in order to obtain both air cooling and water recovery. The system performance is described by different indicators, including the coefficient of performance (COP), gained output ratio (GOR), energy utilization factor (EUF), specific energy consumption (SEC) and specific daily water production (SDWP). The performance indicators are calculated for various climatic zones using a validated analytical model based on the convective heat transfer coefficient. By utilizing the dew point cooling phenomenon, it is possible to minimize the heat and electric energy consumption from external sources, which results in the COP and GOR values being an order of magnitude higher than for other cooling and water recovery technologies. The EUF value of the DPC-WR system ranges from 0.76 to 0.96, with an average of 0.90. The SEC value ranges from 0.5 to 2.0 kWh/m3 and the SDWP value ranges from 100 to 600 L/day/(kg/s). In addition, the DPC-WR system is modular, i.e., it can be multiplied as needed to achieve the required cooling or water recovery capacity.

scholarly journals Evaluasi Kinerja dan Konsumsi Energi Pengering Pati Sagu Model Agitated Fluidized Bed Bertenaga Biomassa

2020 ◽  
Vol 2 (2) ◽  
pp. 53
Author(s):  
Abadi Jading ◽  
Paulus Payung ◽  
Eduard Fransisco Tethool
Keyword(s):  
Energy Consumption ◽  
Fluidized Bed ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Coefficient Of Performance ◽  
Utilization Factor ◽  
Heat Utilization ◽  
Heat Efficiency ◽  
Effective Heat

Pengering Agitated Fluidized Bed (AFB) telah dirancang untuk pengeringan pati sagu. Untuk mengetahui kinerja pengering AFB tersebut, maka dilakukan analisis nilai indeks kinerja Heat Utilization Factor (HUF), Coefficient Of Performance (COP), Effective Heat Efficiency (EHE), dan Specific Energy Consumption (SEC) berdasarkan perlakuan suhu (50oC, 60oC, dan 70oC) dan massa input bahan (3 kg, 6 kg, dan 12 kg). Nilai indeks kinerja HUF, COP, EHE dan SEC ditentukan dengan analisis matematis. Hasil penelitian ini menunjukkan bahwa indeks kinerja pengering AFB terbaik dari semua perlakuan suhu dan massa input bahan adalah pada suhu 60oC dengan massa input bahan 12 kg, dimana nilai HUF lebih besar dari nilai COP. Nilai HUF, COP, dan EHE masing-masing adalah 53,1%, 46,9%, 70,3% dan nilai SEC 559,9 kJ/s. Nilai rata-rata HUF, COP, EHE, dan SEC dari semua perlakuan pada pengering AFB adalah 37,23%, 62,7%, 58,5%, dan 337,6 kJ/s. Kinerja pengering AFB cukup rendah, dimana nilai HUF rata-rata lebih kecil dari nilai COP rata-rata, dan energi yang digunakan cukup tinggi. Namun demikian, pengering AFB mampu mengeringkan pati sagu dengan kadar air akhir 14,4% basis basah mendekati standar mutu pati sagu kering 13%, pada suhu 70oC dengan massa bahan sebanyak 3 kg selama 5 menit (300 detik).

scholarly journals Energetic and exergetic analysis of a convective drier: A case study of potato drying process

2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné
Keyword(s):  
Energy Consumption ◽  
Research Work ◽  
Specific Energy Consumption ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Convective Drying ◽  
Drying Time ◽  
Energy And Exergy ◽  
Exergy Losses

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.

An Overview of Different Indirect and Semi-Indirect Evaporative Cooling System for Study Potency of Nanopore Skinless Bamboo as An Evaporative Cooling New Porous Material

2021 ◽  
Vol 79 (2) ◽  
pp. 123-130
Author(s):  
I Nyoman Suprapta Winaya ◽  
Hendra Wijaksana ◽  
Made Sucipta ◽  
Ainul Ghurri
Keyword(s):  
Energy Consumption ◽  
Porous Material ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Temperature Drop ◽  
High Energy ◽  
Dew Point ◽  
Air Cooling ◽  
Evaporative Cooling System ◽  
Indirect Evaporative Cooling

The high energy consumption of compressor based cooling system has prompted the researchers to study and develop non-compressor based cooling system that less energy consumption, less environment damaging but still has high enough cooling performances. Indirect and semi indirect evaporative cooling system is the feasible non-compressor based cooling systems that can reach the cooling performance required. This two evaporative cooling system has some different in construction, porous material used, airflow scheme and secondary air cooling method used for various applications. This paper would report the cooling performances achieved by those two cooling system in terms of cooling efficiency, cooling capacity, wet bulb effectiveness, dew point effectiveness, and temperature drop. Porous material used in indirect and semi-indirect evaporative cooling would be highlighted in terms of their type, size, thickness and any other feature. The introduction of nanopore skinless bamboo potency as a new porous material for either indirect or semi-indirect evaporative cooling would be described. In the future study of nanopore skinless bamboo, a surface morphology and several hygrothermal test including sorption, water vapor transmission, thermal conductivity test would be applied, before it utilize as a new porous material for direct or semi indirect evaporative cooling.

Influence Factors of Energy Consumption in All Cold Outdoor Air Systems

Solar Energy ◽  
2006 ◽  
Author(s):  
Bing Wei ◽  
Li Li ◽  
Jiang Lu ◽  
Luxiang Zong ◽  
Zhiwei Wang
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Influence Factors ◽  
Operation Time ◽  
Dew Point ◽  
Coefficient Of Performance ◽  
Equivalent Weight ◽  
Outdoor Air ◽  
Full Load ◽  
Full Load Operation

Nowadays the safety of the air conditioning systems is paid more attention to. All cold outdoor air systems due to their particular advantages such as credible safety, better indoor air quality, saving more building space and being in favor of the energy conservation in some given conditions [1] are discussed in this paper. The composing of all cold outdoor air system is outlined and the mathematical models of energy consumption evaluation are presented. With an actual example by using the method of equivalent weight full load operation time, the influence factors to the annual primary energy consumptions in all cold outdoor air systems, such as: the dew point temperature, the COP (Coefficient of Performance) of chiller, the equivalent weight full load operation time of chiller and the efficiency of enthalpy exchanger etc. are compared and analyzed. And the optimal application modes for energy conservation of all cold outdoor air systems are proposed. These can be good references for the application of all cold outdoor air systems.

scholarly journals Quantifying Impacts of Urban Microclimate on a Building Energy Consumption—A Case Study

2019 ◽  
Vol 11 (18) ◽  
pp. 4921 ◽  
Author(s):  
Jiying Liu ◽  
Mohammad Heidarinejad ◽  
Saber Khoshdel Nikkho ◽  
Nicholas W. Mattise ◽  
Jelena Srebric
Keyword(s):  
Energy Consumption ◽  
Convective Heat Transfer Coefficient ◽  
Infiltration Rate ◽  
Building Energy ◽  
Coefficient Of Performance ◽  
Local Temperature ◽  
Urban Microclimate ◽  
Cooling Systems ◽  
College Park ◽  
Building Cooling

This paper considered an actual neighborhood to quantify impacts of the local urban microclimate on energy consumption for an academic building in College Park, USA. Specifically, this study accounted for solar irradiances on building and ground surfaces to evaluate impacts of the local convective heat transfer coefficient (CHTC), infiltration rate, and coefficient of performance (COP) on building cooling systems. Using computational fluid dynamics (CFD) allowed for the calculation of local temperature and velocity values and implementation of the local variables in the building energy simulation (BES) model. The discrepancies among the cases with different CHTCs showed slight influence of CHTCs on sensible load, in which the maximum variations existed 1.95% for sensible cooling load and 3.82% for sensible heating load. The COP analyses indicated windward wall and upstream roof are the best locations for the installation of these cooling systems. This study used adjusted infiltration rate values that take into account the local temperature and velocity. The results indicated the annual cooling and heating energy increased by 2.67% and decreased by 2.18%, respectively.

scholarly journals Design and Energy Consumption Analysis of Small Reverse Osmosis Seawater Desalination Equipment

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2275
Author(s):  
Zhuo Wang ◽  
Yanjie Zhang ◽  
Tao Wang ◽  
Bo Zhang ◽  
Hongwen Ma
Keyword(s):  
Energy Consumption ◽  
Water Resources ◽  
Reverse Osmosis ◽  
Specific Energy Consumption ◽  
Membrane System ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Small Scale ◽  
Reverse Osmosis Membrane ◽  
Seawater Desalination

The reverse osmosis method has developed extremely rapidly in recent years and has become the most competitive seawater desalination technology in the world, and it has been widely used in all aspects. Large-scale reverse osmosis desalination plants cannot provide fresh water resources in areas with insufficient water resources and limited space. Therefore, this paper proposes a research plan for a small seawater desalination device based on reverse osmosis, which is mainly suitable for handling emergencies, disaster relief, desert areas and outdoor activities and other needs for timely freshwater resources. It mainly includes pretreatment modules, a reaction infiltration module, a post-processing module and an energy supply module. Detailed design calculations are carried out for the small-scale reverse osmosis membrane system, including the selection and quantity and arrangement of membranes. Subsequently, the one-stage two-stage small-scale reverse osmosis membrane system was modeled, and its energy consumption was analyzed theoretically from the perspectives of specific energy consumption and energy utilization efficiency; the main influencing factors were clarified, and the optimal recovery rate for system operation was determined to be 20%–30%. Finally, an experimental prototype was built to conduct relevant experiments to determine the influence trend of pressure, temperature, concentration, and flow rate on the operating performance of the reverse osmosis system.

scholarly journals Comparison of Nanofiltration with Reverse Osmosis in Reclaiming Tertiary Treated Municipal Wastewater for Irrigation Purposes

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 32
Author(s):  
MhdAmmar Hafiz ◽  
Alaa H. Hawari ◽  
Radwan Alfahel ◽  
Mohammad K. Hassan ◽  
Ali Altaee
Keyword(s):  
Energy Consumption ◽  
Reverse Osmosis ◽  
Specific Energy ◽  
Recovery Rate ◽  
Municipal Wastewater ◽  
Water Flux ◽  
Applied Pressure ◽  
Specific Energy Consumption ◽  
Water Recovery ◽  
Food And Agriculture

This study compares the performance of nanofiltration (NF) and reverse osmosis (RO) for the reclamation of ultrafiltered municipal wastewater for irrigation of food crops. RO and NF technologies were evaluated at different applied pressures; the performance of each technology was evaluated in terms of water flux, recovery rate, specific energy consumption and quality of permeate. It was found that the permeate from the reverse osmosis (RO) process complied with Food and Agriculture Organization (FAO) standards at pressures applied between 10 and 18 bar. At an applied pressure of 20 bar, the permeate quality did not comply with irrigation water standards in terms of chloride, sodium and calcium concentration. It was found that nanofiltration process was not suitable for the reclamation of wastewater as the concentration of chloride, sodium and calcium exceeded the allowable limits at all applied pressures. In the reverse osmosis process, the highest recovery rate was 36%, which was achieved at a pressure of 16 bar. The specific energy consumption at this applied pressure was 0.56 kWh/m3. The lowest specific energy of 0.46 kWh/m3 was achieved at an applied pressure of 12 bar with a water recovery rate of 32.7%.

Multi-Objective Optimization Design for Cutting Head of Roadheader

2010 ◽  
Vol 450 ◽  
pp. 75-78 ◽  
Author(s):  
Xin Zhang ◽  
Xiao Zhe Liu ◽  
Jian Wu Zhang ◽  
Qing Liang Zeng
Keyword(s):  
Energy Consumption ◽  
Optimization Design ◽  
Specific Energy Consumption ◽  
Mean Value ◽  
Energy Utilization ◽  
Optimization Strategy ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Cutting Head ◽  
Quadratic Programming Method

Aiming at load fluctuations and energy consumption of cutting head, a novel optimization strategy is presented in this paper, which is making every pick loaded uniformly and keeping number of picks in cutting section constant at every moment. It also considers the coal compression-tension effect and the action of pick tilt angle to pick force. The mathematical model of multi-objective optimization design for pick arrangement parameters and motion parameters of cutting head is established firstly, and then the sequential quadratic programming method (SQP) is chosen to compile the program of optimization design. The optimization example shows that in the premise of outline dimensions of cutting head unchanged, the load torque fluctuation decreases for 92%, which reduces the torsional vibration of transmission system of roadheader effectively. The swing force fluctuation also decreases for 83%, which enhances the stability of swing feed. Although the mean value of cutting head’ load decreases a little, all the load peaks decline after optimization, which avoid the single pick overload. And, the specific energy consumption decreases for 21%, which improves the energy utilization of roadheader.

scholarly journals An Overview of Different Indirect and Semi-Indirect Evaporative Cooling System for Study Potency of Nanopore Skinless Bamboo as An Evaporative Cooling New Porous Material

2020 ◽  
Vol 76 (3) ◽  
pp. 109-116
Author(s):  
Hendra Wijaksana ◽  
I. Nyoman Suprapta Winaya ◽  
Made Sucipta ◽  
Ainul Ghurri
Keyword(s):  
Energy Consumption ◽  
Porous Material ◽  
Cooling System ◽  
Evaporative Cooling ◽  
High Energy ◽  
Dew Point ◽  
Air Cooling ◽  
Cooling Systems ◽  
Evaporative Cooling System ◽  
Indirect Evaporative Cooling

The high energy consumption of compressor-based cooling system has prompted the researchers to study and develop non-compressor-based cooling system that less energy consumption, less environment damaging but still has high enough cooling performances. Indirect and semi indirect evaporative cooling system is the feasible non-compressor-based cooling systems that can reach the cooling performance required. These two evaporative cooling systems has some different in construction, porous material used, airflow scheme and secondary air-cooling method used for various applications. This paper would report the cooling performances achieved by those two-cooling systems in terms of cooling efficiency, cooling capacity, wet bulb effectiveness, dew point effectiveness, and temperature drop. Porous material used in indirect and semi-indirect evaporative cooling would be highlighted in terms of their type, size, thickness and any other feature. The introduction of nanopore skinless bamboo potency as a new porous material for either indirect or semi-indirect evaporative cooling would be described. In the future study of nanopore skinless bamboo, a surface morphology and several hygrothermal test including sorption, water vapor transmission, thermal conductivity test would be applied, before it utilizes as a new porous material for direct or semi indirect evaporative cooling.

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